Baggage scanners at Stansted plan a further one-day strike on Thursday after security-scanning company Airfield Services denied a union claim that it used catering workers to check passengers’ luggage during a walk-out yesterday.

Thirty members of the GMB union who scan checked-in luggage went on strike for the day over a pay claim. Stansted operator BAA said there was no disruption or delay to services. A BAA spokesman said: “The airport operated as normal.” About 40,000 passengers departed Stansted on Bank Holiday Monday.

GMB general secretary Paul Kenny said: “The company brought in catering workers to operate security scanners – a clear breach of security standards.”

However, a spokeswoman for Airfield Services said: “All staff had the appropriate training and accreditation. The Department for Transport were on site all day yesterday and were happy with how the operation was managed.”

The company and union remain in talks ahead of Thursday.